In the art of making tubular metal products such as tubes and pipes (hereinafter tubes and pipes will be used interchangeably), one of the processes begins with a sheet or strip of metal. The metal is rolled in such a way to form a desired tube diameter. Then the longitudinal seam of the tube is welded closed. However, the welded seam does not produce a uniform tube wall thickness, and the tube may undergo a process to remove the excess metal from the weld. The debris that results from this removal, commonly referred to as "scarf," often remains in the interior of the tubular product and is undesirable to the consumer for various safety and quality control reasons.
Various operations are available to remove the scarf and debris from the inside of tubes. Generally, pressurized water is forced through the tube to remove the scarf. However, in order for the water to properly flush the tube, a pump is needed to generate a high velocity fluid flow. Pumps and valves used in these operations often experience undue wear caused by differentiating pressures in the system and the "on" and "off" cycling of the pump as the flushing operation is repeated as a plurality of tubes are sequentially advanced through the operation. Of course, cycling the pump "on" and "off" repeatedly lessens the pump's performance and life and causes an effect known as water hammering. Water hammering will result when fluid flow is abruptly stopped, for instance, by a closed valve. The energy in the fluid has no where to go and, therefore, reverberates throughout the system. The energy can damage valves and pumps in fluid flow operations to such an extent that replacement is often required.
The preferred flushing system would operate so that the pump runs continuously and is not subject to intermittent activity. The desired flushing apparatus would also have pressure regulation so that the pressure in the system would be substantially equal throughout the flushing operation and cycling thereof.
Art in the field is directed to processes and apparatuses used in removing scarf and other unwanted materials from the inside of tubular products. However, there is nothing in the art directed to optimizing pump utilization and eliminating water hammering by maintaining continuous fluid flow at substantially constant pressure throughout the system, despite repeated flushing cycles, as with the instant invention. As a result, this invention prolongs the life of a scarf flushing apparatus by eliminating water hammering.